The present invention relates to gynecological instruments generally, and particularly to a uterine tissue collector which scrapes a uterus and collects scraped uterine material by suction.
Obtaining samples of cervical and uterine tissue is normally performed in the art by one of three methods: dilation of the cervix and curettage of the endometrium, known as D and C; suction without dilation of the cervix via a small diameter tube, known as aspiration; or by suction curettage. D and C and suction curettage are capable of collecting as much cervical or uterine material as required, but require anesthesia. Aspiration with a small diameter tube does not normally require anesthesia but is not capable of obtaining amounts of tissue comparable to those obtainable with D and C. In order to obtain amounts of tissue comparable to those obtainable with D and C, aspiration must be performed with a large tube which requires anesthesia.
An endometrial suction curette, called the Pipelle de Cornier, manufactured by PRODIMED of France, may be used to scrape endometrial material with the distal end of a sheath of the curette. However, the scraping area is limited by the relatively small diameter of the sheath and the xe2x80x9cspaghetti-like limpnessxe2x80x9d of the curette.
There are several instruments in the patent literature for scraping a uterus and/or collecting scraped material. U.S. Pat. No. 5,224,488 to Neuffer describes a biopsy needle insertable into a body with a deformable strip which can cut tissue and which protrudes laterally outwards of the needle. The strip does not move back and forth but rather cuts when the user rotates the needle about its axis. The strip is manually pushed laterally outwards of the needle by turning a screw.
U.S. Pat. No. 4,895,166 to Farr describes a rotatable cutter for penetrating into and cutting tissue in a lumen (body cavity). The cutting tool includes two spaced external segments of a conical generally hollow portion with cutting surfaces at their edges. A vacuum is applied to remove fragments of cut tissue. Again the cutter cuts by rotating, not by moving back and forth.
U.S. Pat. No. 5,217,479 to Shuler describes a rotary surgical cutting instrument which cuts with an inner member rotating inside an outer member. The inner member is provided with two symmetric rows of triangular cutting teeth and the outer member has a distal cutting aperture. Here, too, the instrument cuts by rotating, not by moving back and forth.
U.S. Pat. No. 4,340,066 to Shah describes an endometrial sampling device including a cannula which has a transverse slot with scraping edges and a sharp point, and which is insertable into the cervix. By manually moving the cannula and scraping with the scraping edges, one can collect endometrial tissue. The cutter cuts by manually moving the cannula and scraping material, and not by moving back and forth.
U.S. Pat. No. 5,335,671 to Clement describes a surgical assembly for removal of body tissue including a movable cutter inside a cannula which is insertable into a desired location in a patient. The cutter is rigid and cuts by shearing against an aperture in the cannula. A vacuum may be provided for removing cut material. The cutter cuts by shearing in one direction, not by moving back and forth.
Applicant/assignee discloses in PCT Patent Application PCT/US96/02702 and U.S. patent application Ser. No. 08/607,901, the disclosure of which is incorporated herein by reference, a uterine tissue collector including a deformable scraper which is capable of being deformed from an undeformed configuration to a deformed configuration. The scraper scrapes a uterus while moving between the undeformed configuration and the deformed configuration. This uterine tissue collector has already enjoyed much success in clinical trials.
The present invention seeks to provide an improved uterine tissue collector which preferably includes a pair of guide wires that can be used to bend or flex a cannula of the tissue collector to and fro. The cannula is flexible or is constructed with notches or a thin-walled section, so that the cannula tip is bendable. The distal ends of the guide wires are attached to a distal portion of the cannula, and the proximal ends of the guide wires are attached to a finger or hand controlled lever. By pulling on the lever to the right or left, the distal portion of the cannula is accordingly bent or flexed, thereby significantly increasing the area which may be scraped and/or raked. The guide wires may be passed through lumens formed in the cannula or may be internal or external to the cannula.
The present invention also provides a suction device constructed as a two-stage syringe. The syringe has a double barrel, a distal barrel which extends from a proximal barrel, the proximal barrel having a larger diameter than the distal barrel. A plunger sealingly slides in the distal barrel like any conventional plunger. When the plunger is completely pulled proximally through the distal barrel and enters the proximal barrel, the distal tip of the plunger is pulled into engagement with a plunger element so that the plunger element is fixed to the distal tip of the plunger. The plunger element now acts as a new tip of the plunger in its travel in the proximal barrel. Since the proximal barrel has a larger area than the distal barrel, the amount of material which can be collected with the syringe is significantly greater than a conventional syringe of the prior art which has only one barrel of the size of the distal barrel of the present invention, and yet the smaller diameter of the distal barrel allows entry of the syringe of the present invention into smaller openings than possible with syringes of the prior art which have a single barrel of the size of the proximal barrel. Additionally, the arrangement of the proximal and distal barrels ensures a very efficient discharge of all the material collected by the uterine scraper when the plunger is pushed distally to expel the collected material for examination purposes.
As mentioned before, the scraping swath of prior art curettes is significantly limited by the limpness of the curette. In contrast, the combination of the larger diameter proximal barrel and smaller diameter distal barrel provides a structure which is significantly stiffer than the single-diameter curettes of the art. For example, if the distal barrel is one-half the length of a prior art curette, the distal barrel is 8 times stiffer in bending. Of course, the distal barrel is not so rigid that it cannot be bent at all. Rather the combination of the guide wires which flex the distal barrel plus the greater stiffness of the distal barrel, provides a significantly larger scraping swath than was ever possible heretofore in the art.
It is noted that throughout the specification and claims, the term xe2x80x9cuterine tissuexe2x80x9d refers to any material in the cervical canal and uterine cavity, e.g. uterine layering, cervical mucosa, gestational products, endometrium or tumoral substances. In the specification and claims, the term xe2x80x9cuterusxe2x80x9d encompasses the cervical canal and uterine cavity.
There is thus provided in accordance with a preferred embodiment of the present invention a uterine tissue collector including a cannula which has an aperture formed therein through which tissue material can be sucked into a lumen formed in the cannula, and at least one guide wire attached to a distal portion of the cannula, wherein movement of the at least one guide wire flexes the distal portion of the cannula.
In accordance with a preferred embodiment of the present invention the at least one guide wire is disposed through a lumen formed through the cannula.
Further in accordance with a preferred embodiment of the present invention the lumen constrains movement of the at least one guide wire in a direction generally along a longitudinal axis of the cannula.
Still further in accordance with a preferred embodiment of the present invention a proximal portion of the at least one guide wire is pivotally attached about a fulcrum to a lever such that movement of the lever flexes the distal portion of the cannula.
Additionally in accordance with a preferred embodiment of the present invention a pair of such guide wires are provided, wherein generally proximal movement of one of the guide wires causes flexing of the distal portion of the cannula in a direction generally opposite to that caused by generally proximal movement of the other guide wire. Preferably each guide wire is disposed in a separate lumen formed in the cannula.
In accordance with a preferred embodiment of the present invention the at least one guide wire is sufficiently stiff so as to be able to push as well as pull the distal portion of the cannula.
There is also provided in accordance with a preferred embodiment of the present invention a uterine tissue collector including a cannula adapted for insertion into a uterus, the cannula including a scraper for scraping the uterus, and a suction device which sucks material scraped by the scraper, characterized by the suction device including a syringe including a distal barrel which extends from a proximal barrel, the proximal barrel having a larger diameter than the distal barrel, a plunger element disposed about a tube inside the proximal barrel, the plunger element being adapted to sealingly slide inside the proximal barrel, and a plunger that passes through the tube and the plunger element, wherein when the plunger is pulled proximally and starts to enter the proximal barrel, a proximal face of a distal end of the plunger abuts against a shoulder formed in the tube, such that when the plunger is pulled further proximally, the plunger moves together with the tube and the plunger element serves as a new distal end of the plunger during sliding travel in the proximal barrel. Preferably the tube guides and supports the plunger during its travel in the distal barrel. Preferably the uterine tissue collector of the present invention combines both the steering feature and the double barrel suction device feature.